The present invention relates to a multi-directional switch comprising a plurality of manual switches and used in electronic devices such as a portable telephone, video camera, car radio and others.
The multi-directional switch comprises a plurality of fixed contacts circularly arranged in a housing, and an operating plunger tiltably provided in the housing and having a plurality of branches, each having a movable contact which can be contacted with a corresponding fixed contact in the housing by manipulating the operating plunger, thereby producing a specific signal.
FIG. 12 is a sectional side view of a multi-directional switch disclosed in the Japanese Patent Application Laid open 10-188738. There is provided on the bottom of a housing 1 a central fixed contact 2, four peripheral fixed contacts 4, a central movable contact 6 corresponding to the central fixed contact 2, four peripheral movable contacts 7, each provided for a corresponding fixed contact 4, and a circular common fixed contact 3. The central movable contact 6 has a circular tray shape. The peripheral movable contact 7 has a central arcuated yieldable bridge 7a.
A peripheral portion of the central movable contact 6 contacts with the common fixed contact 3 and the central portion of the contact 6 is not contacted with the central fixed contact 2. An inner portion of the peripheral movable contact 7 contacts with the common fixed contact 3, and the bridge 7a is not contacted with the peripheral fixed contact 4.
A first stem 8 and a second stem 10 as an operating plunger are mounted on the movable contacts 6 and 7. The first stem 8 comprises a cylindrical portion 8a and a skirt portion 8b having a spherical peripheral wall. The skirt portion 8b has four projections 8c on the underside thereof, each contacts with a corresponding bridge 7a of the movable contact 7. The first stem 8 is tiltably held by wall of a hole of a cover 11 at the spherical wall thereof.
The second stem 10 has a quadratic prism shape and is vertically slidably mounted in a guide hole 9 of the first stem 8, and prevented from removing from the hole 9 by a flange 10a.
The switches are operated by manipulating the second stem 10. For example, when the second stem 10 is tilted to the left, the first stem 8 is also tilted to the left, so that the projection 8c pushes the bridge 7a to yield it, thereby contacting the bridge to the fixed contact 4. Thus, the contact 4 is electrically connected to the common contact 3 by the bridge 7a. Other switches are similarly operated.
When the second stem 10 is depressed, a projection 10b pushes the central movable contact 6 to yield it so that the movable contact 6 contacts with the fixed contact 2.
In the above described conventional multi-directional switch, the first stem 8 comprises the cylindrical portion 8a and the skirt portion 8b, and the second stem 10 is upwardly projected from the first stem 8. Consequently, the height of the switch becomes large, and hence it is difficult to reduce the thickness and the size of the switch.